Provide a host variable for targets

Now, you can use `${host}` in your `target=`, enabling wildcard matches
in the ini, so that one ini entry can match mutliple hosts with
different passwords successfully.

fixes #7

README.md

@@ -69,6 +69,13 @@ As a consequence, in case you want to use the same account for all github projec
 [github.com*]
 target=dev/github
 ```
+The host can be used as a variable to address a pass entry.
+This is especially helpful for wildcard matches:
+```ini
+[*]
+target=git-logins/${host}
+```
+The above configuration directive will lead to any host that did not match any previous section in the ini file to being looked up under the `git-logins` directory in your passwordstore.
 
 ## Passwordstore Layout
 

pass-git-helper

@@ -109,7 +109,7 @@ def get_password(request, mapping):
             LOGGER.debug('Section "%s" matches requested host "%s"',
                          section, host)
             # TODO handle exceptions
-            pass_target = mapping.get(section, 'target')
+            pass_target = mapping.get(section, 'target').replace("${host}", host)
             skip_password_chars = mapping.getint(
                 section, 'skip_password', fallback=0)
             skip_username_chars = mapping.getint(